There have so far been proposed a wide variety of drive assist display apparatuses for providing a driver with an image taken by a vehicle-mounted camera mounted on such as a rear trunk or a front grille of a vehicle to make the driver sense a backward or a forward of the vehicle.
The conventional drive assist display apparatus is designed to operate a variety of image display methods of, for example, correcting the image for the influence of the deformation of a lens, and converting the image as if taken from any virtual viewpoint.
The conventional drive assist display apparatus of this type is disclosed in a Patent Literature 1.
The Patent Literature 1 discloses a sub view having a display form of a simple rectangle. FIGS. 10 and 12 exemplify two processed images each relating to a display range of a view point conversion image shown in the sub view.
In each of FIGS. 10 and 12, the reference sign 20 indicates a main view showing an image of a wide backward area of the vehicle, the image assumed to be clipped from the taken image.
In FIG. 10, the reference sign 21-1 indicates the sub view showing an image of an area having a width about twice the width of the vehicle, the image obtained by a view point conversion at a vicinity area of the vehicle from the taken image.
In FIG. 12, the reference sign 21-2 indicates the sub view showing an image of an area having a width that at most allows white side lines of a parking space to be displayed, the image obtained by the view point conversion at the vicinity area of the vehicle from the taken image.
In each of FIGS. 10 and 12, the reference signs 22-1 and 22-2 indicate mask picture views filling spaces between the main and sub views without showing any taken image.
In regard to these examples of the processed images, it will be hereinafter explained how the taken image is displayed under a detailed imaging condition.
Firstly described will be a positional relationship between the vehicle-mounted camera constituting a imaging section and the vehicle having the vehicle-mounted camera mounted therein.
The positional relationship is exemplified in each of FIGS. 4 and 5. FIG. 4 shows an overhead view of the backward of the vehicle 1. FIG. 5 shows a side view of the backward of the vehicle 1.
It is assumed that an image of a vicinity of a parking lot is taken.
FIG. 6 shows an example of the parking lot with white lines forming three isometric parking spaces, and isometric vehicles respectively parked in the left and right parking spaces. The reference signs 17-1 and 17-2 indicate the respective parked vehicles each having a height of 1.5 m and assumed to have a shape of a cuboid for better understanding of the present invention.
FIG. 7 shows a positional relationship between the parking lot shown in FIG. 6 and the vehicle 1 trying to park backwardly into the center parking space 16-3.
FIG. 8 shows the taken image before performing an image processing under the state shown in FIG. 7. In this example, the vehicle-mounted camera has a wide-angle lens to take the image of the wide area. Accordingly, the taken image has an image circle 19 appear therein.
In regard to the taken image shown in FIG. 8, the display image is shown as FIG. 10 in accordance with the example shown in FIG. 9.
In FIG. 10, the main view 20 shows the images obtained by cutting away left, right, top and bottom parts from the taken image shown in FIG. 8. In detail, the main view 20 shows an image of an imaging range that moderately covers a part of a bumper 13 of the vehicle 1 in a down side region and parts of the vehicles respectively parked in the left and right parking spaces in an up side region, and has an angle of view about 160 degrees between left and right sides.
In FIG. 10, the sub view 21-1 shows the view point conversion image of the vicinity of the vehicle 1 as if looked down from the virtual viewpoint, and the view point conversion image includes images about half of the vehicles 17-1 and 17-2 in respective left and right side regions.
In general, the whole image of the backward of the vehicle is horizontally flipped before displaying. However, in the description, the whole image of the backward of the vehicle is not horizontally flipped before displaying for better understanding of a left-to-right relationship in the taken image and the display image. Accordingly, the left-to-right relationship regarding the vehicle-mounted camera 2 is same as that of the displayed image.